I simulated a 2D hydrofoil geometry in non-cavitating conditions.
The tested angles are from 0 to 10 degrees and the velocity is constant.
I simulated this hydrofoil using Spalart-Allmaras, k-ε models and k-ω models. Using S-A and k-ω models i have good results for Cl and Cd comparing with experimental results.
But using the k-ε models (standard,rng,realizable) i have good results for Cl but bad results for Cd (as the angle attack increases Cd decreases!)
Also i used enhanced wall treatment (y+=1).

k-ε models cant solve correctly the drag coefficient in hydrofoils?
Please could you help me?